Here are some suggestions:
- Organise terminals automatically by subnet (i.e. some kind of tree view). It would be fine for the admin to have to manually enter the subnets (like in AD Sites & Services). Terminals not having a matching IP could go in a 'default' section.
- Apply templates at the subnet level, so that new terminals automatically pick up those settings without stalling at the "I need a configuration" screen.
- RPi config.txt settings built-in to manager (browser works OK of course, just another step).
- Ability to reboot all terminals in a subnet, for example for new version, with some staggered approach like one terminal per minute (TFTP might be remote and bandwidth limited).